Hi Thierry, welcome to the forums! Yes, you can link to a preference center using the <preferences> tag. Here's more info on this.

As for linking to an alternate version of the campaign, you can use the URL generated by the webversion link. Simply add the <webversion> tags to your campaigns, then send yourself test emails for the campaigns. Once received, click on the webversion links and copy the respective URLs in the browser's address bar. Let me know if you have any questions about this :)